<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
​
<p>搜索字符串 "Runoob", 并显示匹配的起始位置：</p>
<button onclick="myFunction()">点我</button>
<p id="demo"></p>
<script>
function myFunction() {
    var str = "Visit Runoob!"; 
    var n = str.search("Runoob");
    document.getElementById("demo").innerHTML = n;
}
</script>
​
</body>
</html>